package com.wx.util;

  
/** 
     * Created by yuliang on 2015/3/20. 
     */  
public class LocationUtils {  
    private static double EARTH_RADIUS = 6378.137;  
  
    private static double rad(double d) {  
        return d * Math.PI / 180.0;  
    }  
  
    /** 
     * 通过经纬度获取距离(单位：米) 
     * @param lat1 
     * @param lng1 
     * @param lat2 
     * @param lng2 
     * @return 
     */  
    public static double getDistance(double lat1, double lng1, double lat2,  
                                     double lng2) {  
        double radLat1 = rad(lat1);  
        double radLat2 = rad(lat2);  
        double a = radLat1 - radLat2;  
        double b = rad(lng1) - rad(lng2);  
        double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a / 2), 2)  
                + Math.cos(radLat1) * Math.cos(radLat2)  
                * Math.pow(Math.sin(b / 2), 2)));  
        s = s * EARTH_RADIUS;  
        s = Math.round(s * 10000d) / 10000d;  
        s = s*1000;  
        return s;  
    }
    /**  
     * test  
     * @param args  
     */  
    public static void main(String[] args){  
        double distance = getDistance(22.53279,113.38325,22.49716,113.36993);  
        System.out.println("Distance is:"+distance);  
    }  
}  